KENMORE 15612 MAKES SCREAMING SOUND WHEN RUN.

Did you thoroughly oil? Sounds like it has seized because old oil is preventing the parts from moving. Refrain from trying to run the motor until the problem is addressed or you could damage it.

Wheel on right side that controls the needle up and down is very tight...

If it's an older mechanical machine, it may be seized due to old oil that has dried.


Wheel on right side that controls the needle up and down is very tight...

try oiling parts
remove any thread around the bobbin carrier shaft
take it in for a service

Depends on your make/model sewing machine. Older (vintage) mechanical machines need frequent oiling. When one becomes familiar with a sewing machine, it is easy to tell by the change of its sound when it needs some TLC. Avoid running the motor if it sounds stressed--it could damage the motor requiring replacement.

Computerized models should be oiled only as instructed in the manual.

First--use Fresh, good quality sewing machine oil. If it is a computerized machine, there is a lighter weight oil that should be used.

If it is a mechanical machine, the following could be helpful:

Will not zigzag or decorative stitches New to these newer plastic style...

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Service manuals are sometimes difficult to find as the manufacturer intended only technicians would have access to them. Sears, however, carries manuals and parts diagrams for many Kenmore machines. However, they may not be free.

Sounds like your machine has suffered from some neglect over time and has seized from lack of oil (possibly the wrong type of oil). Even though you have oiled it, the old oil has most likely dried out in place preventing the parts from moving freely. Pick up a bottle of liquid Tri-Flow Synthetic Oil from the local hardware or bike shop. While slowly hand-rotating the handwheel, apply a couple drops of oil every place that metal rubs on metal (including the selector dials & levers, feed dog mechanism, etc.). Do not oil plastic parts, cams, or belts.

Then, direct hot air from a handheld hairdryer into the internal mechanics of the machine (be careful because the metal will get hot and can burn your fingers). It may taken multiple applications of alternating oil and hairdryer. This method has worked well for many frozen older machines. Just requires patience and elbow grease (or rather Tri-flow :^O ).

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There are some areas of the machine which cannot be accessed for home servicing - the covers need to be opened up to access them. If the hand wheel is heavy to turn then you may be at the beginning of a needle bar seizure, given the noise at that end of the machine - this will usually sound like a groan. We see this occasionally in machines which have been worked hard without servicing. If you have caught it early, it should be solved by a service at your local sewing centre.
You can loosen the screw on the back and slide the end cover off and put a couple of drops of oil (use only light machine oil) on the top of the needle bar, which will run down to the bearing surfaces, but if that is dry enough to be making noises, the other internal bearings will also be looking for some love.

Did you check to see if the bobbin tension is too tight? That would be the first thing to check.

Clean your machine and oil it. It might just be dirty. I have teh same machine. Also, after that, if teh needle is old it may be dull. This machien can get finicky if the needles are not sharp.

Make sure teh pressure knob at teh top was not released.

Probably need to re-adjust the carburetor jets. They are very small screws in the base of the carburetor. They will be labeled with an "H" and an "L" . Set the low speed first by turning it in slowly until the rpm drops slightly then start turning it outward untill the engine idles smoothly. At that point you can also adjust idle speed. Then you need to be careful here but you need to hold the throttle wide open at the same time adjusting the high speed jet. Turn it in until the rpm drops then slowly turn it out. The rpm will keep increasing. Once you get to a point where it is max'ed out then screw the jet back in one half a turn. Changes in altitude like using your chainsaw in town versus going to the mountains for firewood can sometimes make it necessary to adjust the fuel/air ratio.

try oiling the machine